Device for controlling the opening and closing of a variable shutter for cinematographic photographing apparatus



May l5,1945.. R. WIDMER 2,376,301

DEVICE FOR CONTROLLING THE OPENING AND CLOSING OF A VARIABLE SHUTTER FORCINEMATOGRAPHIC PHOTOGRAPHING APPARATUS Filed July 6, 1945 2Sheets-Sheet l PEA/ Mia ya" Q,

May 15, 1945. R. WIDMER 2,376,301

DEVICE FOR CONTROLLING THE OPENING AND CLOSING OF A VARIABLE- SHUTTERFOR CINEMATOGRAPHIC PHOTOGRAPHING APPARATUS Filed July 6, 1943 2SheetsSheet 2 Patented May 15, 1945 DEVICE FOR CONTROLLING THE OPENINGAND CLOSING OF A VARIABLE SHUTTER FOR CINEMATOGRAPHIC PHOTOGRAPH- INGAPPARATUS Rene Widmer, Sainte-Croix, Switzerland, as

signor to Paillard & Cie. S. A., Sainte-Croix, Switzerland, acorporation of Switzerland Application July 6, 1943, Serial No. 493,681

In Switzerland September 7, 1942 4 Claims.

In cinematographic photographin apparatus there are provided variableshutters with a progressive closing and opening and of which the controlmay be effected either manually or by a mechanism actuated by a separatemotor or by the motor actuating the mechanism of the photographingapparatus. Some of these devices are provided with a shutter formed by,two blades of similar shape and of which the relative displacement maybe modified at will. Each of the blades .is secured to a rotary bodyformed by a sleeve. These two sleeves turn one upon the other and onehas a helicoidal slot while the other has a straight slot extendingalong a generating line. A mechanical connecting member formed by a pinengaging with the two slots connects the sleeves together mechanically.This pin is carried by a support formed by a shaft sliding inside thesleeves. An axial movement of the mechanical connecting member producesa relative angular movement of the two blades.

In some known devices the relative movements of the'blades arecontrolled manually, in others these movements are controlledautomatically. None of these known devices enables these movements to becontrolled indifferently manually or automatically. This is due to thefact that for controlling these movements it is necessary to act on theshaft by means of a member exerting an axial thrust thereon and that itis thus diflicult, without risking jamming, to cause two differentmembers, one of which is controlled manually and the otherautomatically, to act on this shaft.

The present invention has for its subject a control device for a shutterfor a cinematographic photographing apparatus, provided with blades ofwhichone is secured to a sleeve provided with -a helicoidal slot and theother to a sleeve having a straight slot, extending alon a generatingline, these two sleeves being connected togethermechanically in such amanner that an axial movement of a mechanical connecting member producesa relative angular movement of the blades. This device eliminates thedisadvantages referred to by the fact that it is provided with anactuating member exerting an axial thrust on the support of themechanical connecting member, this actuating member being subjected,against a return action, to the action of two actuating mem bers, one ofwhich is operatedautomatically and the other manually.

A form of construction of an actuating device is shown diagrammaticallyand by way of example in the accompanying drawings, wherein:

ig. 1 is a. front view, the-members being in the normal position and theshutteropen.

Fig. 2 is an end view.

Fig; 3 is a partial view in section III-III of Fig. 1.

The variable shutter is formed by two blades 1 and 2, of which one issecured to a sleeve la having a straight slot Ba extending alongagenerating line and the other sleeve 4 turning on the sleeve la. Thewhole is pivoted in bearings 5 and 6 provided in a stationary part. Theshaft 3 is connected mechanically to the sleeves 4 and 4a by means of apin 1 secured to the shaft and engages with the slot 8a of the sleeve 4aand with the helicoidal slot 8 provided in the sleeve l. The latter isdriven by a motor which drives a shaft 9 carryin a helicoidal wheel Illgearing with a helicoidal wheel I l secured to the sleeve l. When themechanical connecting member for the sleeves constituted by the pin 1 isnot subjected to any axial movement, the two blades I and 2 thus turn atthe same speed. Their relative position, however, may be modified atwill during the operation of the apparatus by axial movement of theshaft 3. This variation of the displacement of the blades enables theshutter to be opened or closed progressively so as to obtain fading,that is to say the progressive disappearance or appearance of a scene.

A lever l2, pivoted at 13 on a stationary part, acts on the end of theshaft 3 through the medium of a ball l4 centered on the latter. Thislever 12 has two actuating fingers of which one i5 is adapted toco-operate with a; cam It actuated manually, and of which the otherfinger I1 is adaptedto co-operate with a cam l8 actuated automaticallyby a motor.

The cam I6 is secured to a shaft 22, carrying, at the end thereofemerging to the outside, an operating member (not shown) which isprovided so as to be actuated manually.

The cam l8 issecured to a rocking shaft [3 carrying, amongst othermembers, a toothed wheel 25 and a cam 24 for the locking and theautomatic control of the duration of the relative angular movement ofthe blades of the shutter. The toothed wheel 25 (Fig. 2) gears with apinion 21 loosely mounted on a shaft 28 and carrying one of the parts ofa clutch 29 having only one direction of drive. The second part of theclutch slides on the shaft 28 but is set angularly relatively to thelatter. A spring 3!] presses the two parts of the clutch against oneanother, the pin ion 21 being retained axially by a shoulder 3| of theshaft 28. This latter has a pinion 32 keyed on the line thereto.

The motor is of the spring type one end of the the cam shaft (Fig, 1)and the other to a barrel 34 provided at its periphery with a toothedflange 35. The latter gears with a toothed wheel 36 secured to a pinion38 loosely mounted on a shaft 31. The latter pinion gears with a toothwheel 39 pivoted on an oscillating support 40 securedto a shaft 31. Aspring 4| tends to cause the support 40 and the shaft 31 to oscillate inan anti-clockwise direction. The shaft 31 also carries, rigidly securedthereto, a finger 42 adapted to co-operate with the locking cam 24. Thisfinger is held applied to the profile of this cam by the spring 4|. Anoperating knob 45 enables the shaft 31 to be oscillated, against theaction of the spring 4|, in such a manner as to disengage the finger 42from a notch 43 provided in the cam 24 and which fixes the stop positionof the shaft Hi.

When the finger 42 is disengaged from the notch 43, the toothed wheel 39comes into engagement with the toothed wheel 32. The barrel 34 thendrives the cam shaft l9. The toothed wheels 39 and 32 are maintained inthe engaging position by the finger 42 bearing against a circular partof the cam 24 in such a manner that the operator may release theoperating knob 45 during the duration of fading.

In the position shown in the drawings, the blades 1 and 2 are placed oneabove the other. The variable shutter is thus in its maximum openposition. In face the finger I! is in the bottom of a notch 46 of thecam I8. When this cam turns in an anti-clockwise direction, the fingerI! rises on the ramp 41 which produces an angular movement of the leverI2. This exerts an axial thrust on the shaft 3 through the medium of theball I4. The shaft 3 is moved axially relatively to the two sleeves 4and 4a. This movement controls a displacement of the blades and as theseare no longer covering one another they cover a larger sector.

After a rotation of 180 of the cam Hi, the finger I1 is on the summit 48of the latter. For this position the blades are displaced by 180relatively to one another and completely cover in a notch 46, the bladesare again in their original position. The finger 42 falls at the sametime into the notch 43 of the locking cam and stops |9. This movement ofthe finger 42 enables the support 40 to oscillate under the action ofthe spring 4| and the disengagement of the toothed wheels 32 and 39. Thecam shaft I9 is thus stopped and locked in its normal position, whilstthe mechanism for feeding the film and for actuating the shuttercontinues to be driven by the motor.

For effecting a fading by hand it is sufficient for the operator to turnthe operating knob secured to the shaft 22. The cam I6 is then drivenand controls the movements of the finger of the lever l2.

By turning the shaft 22 in a clockwise direction, the operator controlsthe progressive closing of the shutter. A graduated scale (not shown)engraved on a part secured to the operating member moves opposite afixed mark provided on the the cam 5.

lateral face of the apparatus. This graduated scale indicates to theoperator the relative angular position of the two blades. After completeor partial closing of the shutter, the operator may control aprogressive opening of the blades by turning the shaft 22 in ananti-clockwise dil9 inorder to enable it to be turned for bringing itinto its original position without driving the mechanism for feeding thefilm.

In the form of construction shown in the drawings the cam shaft |9 maybe actuated manually by means of an operating knob 50. The clutch in onedirection of drive isolates the cam shaft mechanically from themechanism for one direction of drive.

By turning the knob 59 in an anti-clockwise direction the cam isactuated in its normal direction of rotation. When thus the finger I! isat 48 it descends the ramp 49 so as to arrive at 46. At this moment thefinger 42 locks the cam shaft Hi. The drive is effected in this casefrom the cam shaft, the teeth of the two parts of the clutch 29 slippingover one another whilst compressing the spring 30 so that the entiremechanism for feeding the film and driving the shutter remainsstationary during this operation.

This clutch which only drives in one direction also enables the motor ofthe apparatus to be wound after a fading out without modifying theposition of the cam shaft l9. In fact, for rewinding the spring, thetoothed flange 35 is actuated in a direction opposite to the normaldirection of operation so that the teeth of the two parts of the clutch29 slip over one another.

A form of construction of the subject of the invention has beendescribed above by way of example, but it will be understood that anyequivalent mechanical device may be used.

For example the fingers I5 and I1 may be replaced by pushers sliding inguides or pivoting on a stationary shaft and subjected to the action ofsprings tending to hold them in contacts with their respective cams,these pushers being capable of actuating the lever |2 independently ofone another.

It may be observed that the variable shutter enables the time ofexposure to be modified without changing the speed of feeding the filmthat is to say without changing the number of shots effected in a unitof time. In fact the displacement of the blades and thus the angle ofopening of the blades may be selected at will by operating Finally,irrespective of the position of this cam,the automatic control of thecomplete closing and partial opening of the blades is effected inexactly the same manner as described above. In this case, during theautomatic control of the closing of the blades, the finger H is onlyactuated after an angular movement of the cam l8, which movement variesaccording to the position of the cam |6. Further, duringthe automaticcontrol of the opening of the blades, the finger |1 leaves the cam- I8when-their opening corresponds: with" the opening a'dju'stedby the camI6.-

Having now particularly described and ascertained the nature of my saidinvention and in what manner the-same is to be performed, I declare thatwhat I claim is:

1. A device for controlling a shutter for cinematographic photographingapparatus comprising film feeding means, a pair of coaxially andconcentrically mounted hollow shafts, a shutter blade mounted on one endof each of said shafts, a helicoidal slot formed in the wall of one ofsaid shafts and a straight slot extending along a generating line formedin the other, of said shafts, a third shaft concentrically and coaxiallymounted with respect to said first two shafts, said third shaft beingprovided with a pin adapted to cooperate with said slots, resilientmeans cooperating with said third shaft to constantly urge said pintoward one end of said slots, a pivoted actuating member, said actuatingmember having one of its ends in abutting relationship with one end ofsaid third shaft, the other end of said member being bifurcated, amanually operated cam engaging one of said bifurcations and anautomatically operating cam engaging the other of said bifurcations,said cams adapted to be ro- 'tated independently, and upon rotation ofeither of said cams said actuating member changes its angular positionand axially displaces said third shaft whereby the angular position ofsaid blades is-correspondingly modified.

2. A device for controlling a shutter for cinematographic photographingapparatus as defined in claim 1, and means for connecting said auto--locking cam, said locking cam and said automatic cam being rigidlysecured to said cam shaft, a pivoted element, one end of said elementbeing adapted to engage the profile of locking cam, and a gear trainmounted on the other end of said element, said motor beinginterconnected with said gear train, and means for oscillating saidelement out of locking position with said locking cam whereby said geartrain may be brought into engagement with said gear.

4. A device for controlling a shutter for cinematographic photographingapparatus as defined in claim 1, and a cam shaft, a locking cam andmotor means for driving said film feed means and said shutter, saidlocking cam and said automatically operating cam being rigidly securedto said cam shaft, and means for rotating said locking cam into lockedposition from any position independently of said film feeding means.

RENE WIDMER.

